This invention relates to materials suitable for candle bodies which candle bodies include compositions of matter which are both (i) efficaciously insect repelling and (ii) perfuming in an aesthetically pleasing manner on use thereof.
Formulations exist in commerce which are said to provide candle body materials that are both perfuming and insect repellent but such formulations have yielded a candle body that is either insufficiently insect repellent or aesthetically displeasing from an organoleptic standpoint.
When a candle burns, the heat of its flame melts a small pool of the candle body material around the base of the exposed portion of the wick, and this molten material is drawn up through the wick by capillary attraction to fuel the flame. Thus the process that takes place in the burning of a candle imposes rather stringent functional requirements upon the candle body material.
The material of a candle body must be rigid enough to support itself and a relatively long wick filament, but it should not be excessively brittle at low temperatures. Its melting point is critical, in that it should liquify temperatures, to which, it can be raised by radiant heat from the candle flame. If its melting temperature is too low, the candle will drip or, in an extreme case, the entire candle body will melt, dropping the wick into a pool of molten material with the hazardous possibility that the surface of the pool will iqnite when this happens. If too high a temperature is required to melt the body material, the flame will be starved because insufficient fuel will be drawn up through the wick, with the result that the flame will be too small to maintain itself. When molten, moreover, the candle body material must have a relatively low viscosity in order to insure that it will be capable of being drawn up through the wick by capillary action.
In addition to meeting these requirements the candle body material must burn with a flame that is both luminous and smokeless and such odors as are produced by its combustion should not be unpleasant and should preferably be faint.
The functional requirements outlined above have, of course, been met by various candle body materials that are well known in the art, but heretofore no known materials that meets these requirements has been both:
(a) Perfuming to the environment surrounding the burning candle; and PA1 (b) Adequately insect repellent to the environment surrounding the material at various environmental temperatures at atmospheric pressure, from a temperature of about 0.degree. C. up to a temperature of about 50.degree. C. PA1 (a) From about 35% up to about 85% by weight of an oil which is normally liquid at room temperature which may be light mineral oil and a natural oil; PA1 (b) From about 7% up to about 40% by weight of a long chain polyamide having a molecular weight between 6,000 and 9,000 and a softening point within the range of 185.degree. C.-48.degree. C. from about 7% up to about 30% by weight of an alcohol which may be a C.sub.8 up to a C.sub.12 primary alcohol. PA1 Insect repellent contains benzalacetone (I) as active component. (I) has an immediate effect used in combination with sublimating substance such as naphthalene and camphor. The ratio of blend of benzalacetone to the sublimating substance is 90:1-5:95. Opt. excipient such as silica gel, talc and binder such as PVA or CMC. and aromatic substance can be added (I) can be put in a suitable vessel, can be prepd. as tablet, or can be supported on cloth or paper. PA1 (I) From 5 up to 100% by weight of an efficacious perfuming/insect repelling composition consisting essentially of: PA1 (II) From 0 up to 95% by weight of a standard perfuming substance (non-insect-repelling) which may be one or a combination of the following materials: PA1 (i) A thermoplastic polyamide resin formed from linoleic acid polymerized with a polyamine compound; PA1 (ii) An alkanol amide or alkanol amine; and PA1 (iii) A stearic acid compound. PA1 (a) from about 35% up to about 85% by weight of an oil which is normally liquid at room temperature chosen from the group consisting of light mineral oil and natural oils having iodine values substantially within the range of 40-135; PA1 (b) from about 7% to about 40% by weight of a long chain polyamide having a molecular weight substantially within the range of 6000-9000 and a softening point substantially within the range of 185.degree. C.-48.degree. C.; and PA1 (c) from about 7% to about 30% of an alcohol selected from the group consisting of 8 to 12 carbon primary alcohols.
However, the desire for such a candle body material which is either transparent, opaque or translucent has long persisted where the candle composition is both insect repellent and perfuming on use.
An article by Burton, "Intrinsic mosquito repellency values of some chemical compounds" appearing in Volume 84, American Perfumer and Cosmetics, April, 1969 at page 41, indicates that Coumarin has a value of from 0.001 up to 0.003 micromoles per liter of air for 90% insect repulsion. It further states that Indole has a property such that 0.004 up to 0.01 micromoles per liter of air of Indole are needed for 90% insect repulsion. On the other hand the article by Burton indicates that a compound such as Linalool requires 0.1 micromoles per liter of Linalool per liter of air for 90% insect repulsion.
Nothing is stated in the Burton article which causes one to be taught that Coumarin and Indole taken in combination can be added to citronella oil or one or more methyl heptenones whereby the efficacy of the overall composition is maintained or increased and the overall concentration of insect repelling mixture is substantially diminished while at the same time causing an aesthetically pleasing aroma to be emanated from the burning candle on use.
Currently on the market are "citronella oil candles" containing approximately 1.5-3% citronella oil. On use these candles give off an essentially aesthetically displeasing aroma and are not quite as effective in repelling insects as desired by the user.
U.S. Pat. No. 3,615,289 issued on Oct. 26, 1971 discloses candle compositions which may be transparent or pastel shaded which are adapted to incorporate perfumes without flashing during burning, and such compositions comprise as the basic components the mixture of (i) a thermoplastic polyamide resin formed from linoleic acid polymerized with a polyamine compound; (ii) an alkanol amide or alkanol amine; and (iii) a stearic acid compound. More Specifically, U.S. Pat. No. 3,615,289 specifically discloses and claims a candle composition comprising about 15 to 35% by weight of a solid gel thermoplastic polymer which is a solid polyamide resin which is the soluble condensation product of an aliphatic dicarboxylic acid and an amine, the carboxyly and amino groups of adjacent mono units being condensed to an amide linkage in the polymer (and the resin may also be based on carboxylic and amine compounds having more than two carboxyl and amino groups respectively). At column 3, line 10 of U.S. Pat. No. 3,615,289 it is indicated that the candle contain about 0.4% by weight of a perfume material. Claim 3 at column 4 of U.S. Pat. No. 3,615,289 discloses a composition wherein 5 to 7% of the composition is replaced by a coumarone-indene copolymer resin. The insect repellency of compositions usable in U.S. Pat. No. 3,615,289 is not disclosed however.
U.S. Pat. No. 3,645,705 discloses a transparent candle body composition of matter which can contain:
At column 3, line 56 of U.S. Pat. No. 3,645,705 it is disclosed that an odor masking agent may be incorporated into the candle composition. Generally this disclosure is set forth at lines 30-44 of U.S. Pat. No. 3,645,705 thusly:
"The inclusion in the composition of certain alcohols that produce otherwise desirable properties may result in a material that burns with an acrid or pungent odor. In such cases a small amount of an odor masking agent can be incorporated in the composition. The material sold by Fritzsche, Dodge and Olcott as its No. 41984 has been found satisfactory when incorporated in the composition in amounts up to about 0.2 percent by weight. The odor-masking agent is desirable when less expensive alcohols are used and may be unnecessary if the alcohols are highly refined, but from the standpoint of cost, the use of the cheaper alcohols and an odor-masking agent is indicated and produces satisfactory results. If desired, a small amount of perfume can be added to the composition to complete the odor-masking effect."
Nothing in U.S. Pat. No. 3,645,705, however, discloses the applicability to the composition disclosed therein of insect repellent materials. Nothing discloses the use of a composition of matter in U.S. Pat. No. 3,645,705 which will be both a perfumant and an insect repellent.
U.S. Pat. No. 4,051,159 issued on Sept. 27, 1977 discloses a "shaped, self-supporting transparent fragrance emitting article comprising a high percentage of a thermoplastic polyamide resin having substantially uniformly dispersed therein a C.sub.14 -C.sub.22 alkyl alcohol and a fragrance emitting material". U.S. Pat. No. 4,051,159 however, does not indicate that the compositions of matter disclosed therein are useful for the purposes of candles and particularly are useful for fragrant candles or insect repellent candles or candles which are both fragrance emitting and insect repellent.
Published Japanese patent application J57088-101 assigned to the Agency of Industrial Sci. Tech. of Japan discloses the use of benzal acetone, 1-carvone thymol as insect repelling materials contained in conjunction with an aromatic substance, silica gel, talc or a binder such as polyvinyl alcohol or carboxymethyl cellulose.
Published Japanese patent application 57088-101 however, does not indicate that compositions of matter are useful for the purposes of candles and particularly, are useful for fragrant candles or insect repellent candles or candles which are both fragrancy emitting and insect repellent in an efficacious manner. The abstract of published Japanese application J57088-101 is as follows:
Benzalacetone has the m.pt. of 41-42 deg.C and the b.pt. of 260-262 deg.C. The satd. gas concn. of benzalacetone is 0.045 mg/l by gas chromatography and is one tenth that of 1-carvone and one third that of thymol, and therefore it has long-lasting effect.
(I) is nontoxic to warm-blooded animals, and shows repelling effect for a long period of time. It is prepd. in low cost, and can be stored in plastic vessel, since it does not etch plastics. It is particularly effective in the repelling of insects for clothes, e.g. Tinea pellionella. (3pp)